<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
      <div id="app">
        <h3>双向绑定 修改框里值 后面的值也会变 修改app.msg input也会变</h3>
        <input type="text" v-model="msg">
        {{msg}}
      </div>
      <script src="../js/vue.js"></script>
      <script>
          var app=new Vue({
             el:'#app',
             data:{
               msg:'ABC'
             },
             methods:{}
          });
      </script>

</body>
</html>